1. Field of the Invention
The present invention relates to an image processing apparatus detecting a scene and, in particular, to an image processing apparatus, an image processing method, and a computer program for detecting a scene containing a selected object.
2. Description of the Related Art
As prices of memories are reduced and technology of the memory advances, the capacity of memories in image pickup apparatuses such as digital still cameras and digital video cameras increases. The number of moving images stored on the image pickup apparatuses also increases. Under this circumference, there is a need for techniques that allow users to view a predetermined scene of a desired moving image. Known techniques cannot detect a scene centered on a subject desired by the user from the moving image captured by the image pickup apparatus such as digital still cameras and digital video cameras.
Japanese Unexamined Patent Application Publication No. 5-204990 discloses a technique addressing this problem. In accordance with the disclosed technique, an area of a frame constructing a moving image is selected, the frame containing an image surrounded within the area is found, a period within which the found frames are continuous with each other is selected as one scene, and a keyword is imparted to the period to help a user search for the scene of the moving image. In accordance with this technique, a predetermined condition is set on space between partial periods where the found frames are consecutive, and when the predetermined condition is satisfied, the partial periods are linked to each other to form one scene. The predetermined condition for linking the partial periods is that the number of frames interposed between one partial period and another partial period is set to be a predetermined number or less. In another technique, an image of an object desired by the user is set to be a template image, the template image and a frame constructing the moving image are matched against each other so that a set of frames containing an image similar to the template image is handled as one scene.
In the technique disclosed in Japanese Unexamined Patent Application Publication No. 5-204990, periods having the consecutive found frames are selected as one scene. If one condition that the number of frames interposed between one partial period and another partial period is equal to or less than a predetermined number is satisfied, the periods are linked as one scene regardless of the content consistency of the scene. A definitely unrelated scene may be contained in one scene. In the other technique, the template image and the frame constructing the moving image are matched against each other and the set of frames containing images similar to the template image are handled as one scene. A frame in which a subject temporarily happens to look to a different direction in the moving image is not handled as a frame containing the images similar to the template image. The scene that should be otherwise within one group can be split.
It is thus desirable to provide an image processing apparatus for detecting accurately a scene where a targeted object appears in a moving image.